The quantitative detection of the uptake and intracellular fate of albumin nanoparticles

Abstract

Little has been investigated about the intracellular fate of organic nanoparticles (NPs), which is important for the safety and drug delivery efficiency of NPs. In this study, to understand the NP cellular uptake and degradation characteristics, a quantitative method based on fluorescence resonance energy transfer (FRET) was developed and validated to detect the uptake and intracellular degradation of albumin NPs in MCF-7 cells. The effects of the crosslinking density and particle size on the intracellular uptake and degradation kinetics of albumin NPs were then systematically detected. The results indicated that the albumin NPs with higher crosslinking degrees could be internalized more quickly. With increasing NP diameter, the uptake number of NPs decreased, but the uptake NP weight increased due to the compensation of the increased weight of a single particle. The intracellular degradation results showed the NPs with a low crosslinking degree or a small diameter dissociated more quickly in cells, and the half-lives for the albumin NP dissociation were in the range of 35–79 h. These findings will provide fundamental but direct information for the optimal design and biomedical applications of NPs based on their intracellular fates, and the FRET method developed in this study can provide a novel and robust tool to track and monitor the NP intracellular fate.